Why our brains cherish humanity: Mirror neurons and colamus humanitatem JOHN R. SKOYLES* Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX) University College London, London, UK Centre for Philosophy of Natural and Social Science (CNPSS) London School of Economics, London, UK Abstract Resumen Commonsense says we are isolated. After all, our El sentido común dice que estamos aislados. Des- bodies are physically separate. But Seneca’s cola- pués de todo, nuestros cuerpos están separados mus humanitatem, and John Donne’s observation físicamente. Pero la obra Colamus humanitatem that “no man is an island” suggests we are neither de Séneca y la observación de que “ningún hombre entirely isolated nor separate. A recent discovery in es una isla”, que hizo John Donne, sugieren que no neuroscience—that of mirror neurons—argues that estamos ni completamente aislados ni separados. the brain and the mind is neither built nor functions Un descubrimiento reciente de la neurociencia, el remote from what happens in other individuals. de las neuronas espejo, sostiene que el cerebro y What are mirror neurons? They are brain cells la mente no son construidos ni funcionan alejados that process both what happens to or is done by an de lo que pasa en otros individuos. ¿Qué son las individual, and, as it were, its perceived “refl ec- neuronas espejo? Son células cerebrales que pro- tion,” when that same thing happens or is done by cesan tanto lo que le pasa como lo que hace un in- another individual. Thus, mirror neurons are both dividuo, y, por así decirlo, su “refl exión” percibida activated when an individual does a particular ac- cuando esa misma cosa le pasa a, o es hecha por, tion, and when that individual perceives that same otro individuo. Por lo tanto, las neuronas espejo action done by another. The discovery of mirror se activan cuando una persona realiza una acción neurons suggests we need to radically revise our específi ca y cuando percibe la misma acción rea- notions of human nature since they offer a means lizada por otro. El descubrimiento de las neuronas by which we may not be so separated as we think. espejo indica que es preciso revisar radicalmente Humans unlike other apes are adapted to mirror nuestras nociones sobre la naturaleza humana, ya interact nonverbally when together. Notably, our que estas neuronas ofrecen un medio por el cual no faces have been evolved to display agile and nim- concebimos estar tan separados como pensamos. ble movements. While this is usually explained A diferencia de otros simios, los humanos están as enabling nonverbal communication, a better adaptados a interactuar de forma similar no verbal, description would be nonverbal commune based cuando están juntos. De manera particular, nuestras upon mirror neurons. I argue we cherish humanity, caras han evolucionado para mostrar movimientos colamus humanitatem, because mirror neurons and ágiles y rápidos. Mientras esto usualmente expli- our adapted mirror interpersonal interface blur the ca cómo se logra la comunicación no verbal, una physical boundaries that separate us. mejor descripción sería la comunicación no verbal * Please send correspondence to: John R. Skoyles. Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoM- PLEX), University College London. 4 Stephenson Way, London NW1, 2HE, UK. E-mail: [email protected]. Avances en Psicología Latinoamericana/Bogotá (Colombia)/Vol. 26(1)/pp. 99-111/2008/ISSN1794-4724 99 John R. Skoyles Key words: mirror neurons, empathy, self, social basada en las neuronas espejo. El autor sostiene emotions, interpersonal communication, commu- que valoramos la humanidad, colamus humanita- nitas. tem, porque las neuronas espejo y nuestra interfaz interpersonal adaptada de espejo desdibujan las fronteras que nos separan. Palabras clave: neuronas espejo, empatía, sí mismo, emociones sociales, comunicación inter- personal, sentido de comunidad. Why cherish humanity—Seneca’s colamus huma- isolated as if were an island. As the social psycholo- nitatem? Why care about other people? Why should gist James Fiske has observed: “From Freud to so- we go beyond the boundaries of our own personal ciobiologists, from Skinner to social cognitionists, lives and value the lives of other men and women? from Goffman to game theorists, the assumption in Is it, perhaps, because we are all members of the Western psychology has been that humans are by same species, Homo sapiens sapiens? Or, maybe, nature asocial individualists ... social relationships it is because when I see another person in pain, I are instrumental means to nonsocial ends, or cons- know rationally that what they experience is much traints on the satisfaction of individual desires” the same as when I suffer myself pain? But these (1992, p. 689). And again, as another psychologist, answers are not by themselves convincing: for, C. Daniel Batson has observed, “Perhaps the rea- why should the fact that other people are like me son that psychologists have spent little time on the either in body or in their capacity for experiences question of our social nature is because they already such as pain, cause me to care or cherish them? know the answer... our behavior may be highly so- We do this—and feel we ought to—but it is not cial; our thoughts also may be highly social; but in a logical necessity. After all, the cells of my body our hearts, we live alone... We are social egoists” under the microscope might be much like those of (1990, p. 336). earthworms or some other lowly creature but that Neuroscience, as I will show here, provides does not mean I should necessarily value the life of grounds for rejecting the idea that we are “asocial earthworms. Yet Seneca’s observation about 2000 individualists” and “social egoists.” By contrast, years ago touches a deep insight as to human na- we now know that the neural fabric out of which ture and what it is to be a human. An unidentifi ed each of our minds is woven is such that the lives and aspect about being a human exists that causes us experiences of other people are as vital to us as our to cherish other people. As John Donne once noted own. The neuroscience discovery which is respon- in his Devotions that “no man is an island, entire sible for this goes by the name of “mirror neurons.” to itself,” and “Any man’s death diminishes me, These neurons, I shall argue, support John Donne because I am involved in Mankind.” Here poets and Seneca’s view of human nature. Neurologica- catch a truth—but what kind of truth is it—for it is lly, no brain is an island. Our neurons wire us to not one of logic. Can science illuminate this aspect exist within, to use a Latin word for “common”, as of our unknown humanity? a nonverbal communio, or commune. Here, however, is not a problem that most psy- chologists and philosophers seek to fathom. Rather What are mirror neurons? scholarly and scientifi c attempts to understand the nature of humanity mostly start from the premise To understand mirror neurons, we need fi rst to that other people’s experience does not funda- appreciate how the brain was traditionally—and mentally matter. Yes, people may say words about mistakenly—thought to work. If one looks at a valuing others for courteous appearances but that diagram of the brain, it is labeled with terms such underneath each of our minds really in fact lives as as visual, auditory and motor. Thus, there is the 100Avances en Psicología Latinoamericana/Bogotá (Colombia)/Vol. 26(1)/pp. 99-111/2008/ISSN1794-4724 Why our brains cherish humanity: Mirror neurons and colamus humanitatem visual cortex at the back of the brain that indicates applies to actions done by bodies – those done by that this area handles sight, and the motor cortex robots do not activate these neurons (Tai, Scherfl er, in the front that this area deals with the body’s Brooks, Sawamoto, & Castiello, 2004). Such brain movements. These areas have divisions; hence areas respond, moreover, not only to the sight of the motor cortex gets divided up, for example, other movements but also their perception through into the primary motor cortex and the premotor sound (Galati et al., 2008). (This might seem an cortex. There are good reasons for the existence obscure point but in fact our vocal ability to pro- of these terms—injury to the visual cortex causes nounce a word or name that we have just overheard blindness and, likewise, injury to the motor cortex depends upon such auditory-motor mirroring.) The causes paralysis. This labeling has turned out howe- activation of mirror neurons occurs even when the ver to cause false expectations about the workings object of an action is hidden, provided the intention of the brain. One of them is that the function of the of the goal of the movement is clear (Umilta et al., motor cortex areas does not include also an impor- 2001). Mirroring applies to emotional expression tant role in perception. After all, labels for percep- and experience also, for example, when we see the tion such as vision and audition have been given to expression of disgust on the face of another person parts of the brain elsewhere. So it was unexpected after smelling a revolting odor, we activate the sa- when in 1992 that Giacomo Rizzolatti and collea- me areas in our own brain (the anterior insular—a gues of Parma University (1992) found that certain part of the emotional brain near the motor cortex) neurons in a part of the motor cortex, the F5 inferior that gets activated when we ourselves smell that premotor area, had a role in perception.